GD Image Verification

Have you ever wondered how some websites make you put in those numbers or phrases to verify that it is a human posting and not just a bot trying to spam the website? Well wonder no more!

Creates an image with random text and numbers, then outputs it to the screen, or saves it to a file on your server. When it does the number/lettering, it will make them have different spacing and x,y positioning each time.

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Izzmo

Posted 146 Days Ago

Well, it's stored in a session key. That's how you verify it. I do not that it is easy to crack, never said it wasn't, but it is just a basic example. But, just to tell you, having this on my site, I have had 0, that's right 0, SPAM accounts setup.

VBAssassin

Posted 146 Days Ago

Nice, but pointless. Sorry, let me explain. 1. There is too much contrast - the worst (easiest to crack) is black and white lol. There's some software (on sourceforge i think) that is open source and cracks week validation images - yours would be very very very easy to crack. 2. Ok, so you've added some alphanumeric characters to an image... now how do you get the script using it to verify that the user typed in what was on the image? You can't! Not with that script anyway. Try using a session or something similar. 3. There's nothing stopping other websites hotlinking it and using it for their own site. Try adding an include key i.e. a special key that the script requires before it will execute - which can be set in a session by the page using the validation image. That will stop people stealing the image and your server resources because they won't know the key they must set in order to use the image ;-) again, setting a session will also help solve this because the session will be created on your server, not the server stealing the image. Kind regards, Scott

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